The full-length protein encoded by this gene is an intracellular tetrapyrrole-binding protein. This protein includes a natural chemoattractant peptide of 21 amino acids at the N-terminus, which is a natural ligand for formyl peptide receptor-like receptor 2 (FPRL2) and promotes calcium mobilization and chemotaxis in monocytes and dendritic cells.[5]
Jacob Blackmon B, Dailey TA, Lianchun X, Dailey HA (Nov 2002). "Characterization of a human and mouse tetrapyrrole-binding protein". Archives of Biochemistry and Biophysics. 407 (2): 196–201. doi:10.1016/s0003-9861(02)00471-x. PMID12413491.
Zylka MJ, Reppert SM (Dec 1999). "Discovery of a putative heme-binding protein family (SOUL/HBP) by two-tissue suppression subtractive hybridization and database searches". Brain Research. Molecular Brain Research. 74 (1–2): 175–81. doi:10.1016/s0169-328x(99)00277-6. PMID10640688.